1. Field of the Invention
This invention relates to a spanner shaping method and relates particularly to a method of making a spanner capable of reducing the waste of the material, shortening the processing time and decreasing the cost.
2. Description of the Related Art
Referring to FIG. 1 and FIG. 2, a traditional method 1 of making a spanner S1 is carried out by hot forging. The method 1 comprises a preparing step 11, a cutting step 12, a heating step 13, a punching step 14, a cooling step 15 and a removing step 16. The preparing step 11 prepares a rolled round metal blank a. The cutting step 12 cuts the blank a into a proper length. The heating step 13 applies a heater 131 providing a fixed and high temperature to heat and soften the blank a. A punch 141 and dies 142 disposed on the punch 141 and provided with a shaping impress are used in the punching step 14. The punching step 14 puts the heated and softened blank a on the dies 142, pressurizes the round blank a to form a flat blank al and presses the flat blank al to build an impression of a spanner outline R. The cooling step 15 cools the impressed flat blank al. The removing step 16 prepares a removing machine 161 to remove the residual metal along the peripheral edge of the spanner outline R. Therefore, a finished spanner S1 is completed. However, such heating method requires a high cost for processing with correlated heating machines. Further, the heated blank al can only be shaped after the cooling step 15 is done, and this requires more complicated actions and takes much time.
Referring to FIG. 3 and FIG. 4, a further traditional method 3 of making a spanner S2 is carried out by cold forging. The method 3 comprises a preparing step 31, a head forming step 32, a stamping 33 and a removing step 34. The preparing step 31 prepares a round metal blank b. The head forming step 32 is executed by cold-forging two ends of the round metal blank b to form two round heads h. The stamping 33 uses a stamping press (not shown) to press the round metal blank b with two round heads h whereby the round metal blank b is formed into a flat blank b1 with a spanner outline. The removing step 34 removes the residual metal along the peripheral edge of the spanner outline of the flat blank b1 with another stamping press (not shown). Therefore, a finished spanner S2 is completed. Generally, because the round metal blank b and the round heads h formed at two ends thereof are thick, the metal blank b must be pressed by a particular press. The stamping step 33, however, must prepare a stamping press whose power output and weight is much larger than those of the press used in the head forming step 32 to provide enough driving forces to press the round metal blank b into the flat blank b1 and shape the spanner outline. Therefore, the bulk and the cost of the necessary stamping presses used in the above steps may be much higher than those of the common stamping presses, and this usually increases the processing cost for making the finished spanner S2.